随机字符串工具类
示例代码：
import java.io.UnsupportedEncodingException;
import java.security.SecureRandom;
import java.util.*;
/**
* 随机生成字符串
*/
public final class RandomStringUtil {
/**
* 2021年姓排行100
*/
private final static String[] SURNAME = {
"李", "王", "张", "刘", "陈",
"杨", "赵", "黄", "周", "吴",
"徐", "孙", "胡", "朱", "高",
"林", "何", "郭", "马", "罗",
"梁", "宋", "郑", "谢", "韩",
"唐", "冯", "于", "董", "萧",
"程", "曹", "袁", "邓", "许",
"傅", "沈", "曾", "彭", "吕",
"苏", "卢", "蒋", "蔡", "贾",
"丁", "魏", "薛", "叶", "阎",
"余", "潘", "杜", "戴", "夏",
"钟", "汪", "田", "任", "姜",
"范", "方", "石", "姚", "谭",
"廖", "邹", "熊", "金", "陆",
"郝", "孔", "白", "崔", "康",
"毛", "邱", "秦", "江", "史",
"顾", "侯", "邵", "孟", "龙",
"万", "段", "漕", "钱", "汤",
"尹", "黎", "易", "常", "武",
"乔", "贺", "赖", "龚", "文"};
private static final char LOWER_CHAR[] = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y'};
private static final char UPPER_CHAR[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y'};
private static final char NUMBER_CHAR[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9'};
public static final int MULTIPLE = 0;// 所有字符
public static final int LOWER = 1;// 只包含小写字母
public static final int UPPER = 2;// 只包含大写字母
public static final int NUMBER = 3;// 只包含数字
public static final int LOWER_AND_UPPER = 4;// 包含大小写字母
public static final int LOWER_AND_NUMBER = 5;// 包含小写字母和数字
public static final int UPPER_AND_NUMBER = 6;// 包含大写字母和数字
/**
* 随机获取姓名
*
* @return
*/
public static String fullName() {
return surname() + name(2);
}
/**
* 拼接字符数组
*/
public static char[] concat(char[]... a) {
LinkedList<Character> list = new LinkedList<>();
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a[i].length; j++) {
list.add(a[i][j]);
}
}
char result[] = new char[list.size()];
Iterator<Character> it = list.iterator();
for (int i = 0, length = result.length; i < length; i++) {
result[i] = it.next();
}
return result;
}
/**
* 获取随机字符串，包含大小写字母和数字，可以有重复字符
*
* @param length 字符串长度
*/
public String getRandomString(int length) {
return getRandomString(length, MULTIPLE, true);
}
/**
* 获取随机字符串，可以有重复字符
*
* @param length 字符串长度
* @param randomType 随机字符的类型
*/
public String getRandomString(int length, int randomType) {
return getRandomString(length, randomType, true);
}
/**
* 获取随机字符串
*
* @param length 字符串长度
* @param randomType 随机字符的类型
* @param repeat 是否可以有重复字符，true表示可以重复，false表示不允许重复。如果length大于randomType库的长度，则默认采用true值。
*/
public static String getRandomString(int length, int randomType, boolean repeat) {
StringBuilder sb = new StringBuilder();
char find[] = null;
switch (randomType) {
case LOWER:
find = LOWER_CHAR;
break;
case UPPER:
find = UPPER_CHAR;
break;
case NUMBER:
find = NUMBER_CHAR;
break;
case MULTIPLE:
find = concat(LOWER_CHAR, UPPER_CHAR, NUMBER_CHAR);
break;
case LOWER_AND_NUMBER:
find = concat(LOWER_CHAR, NUMBER_CHAR);
break;
case UPPER_AND_NUMBER:
find = concat(UPPER_CHAR, NUMBER_CHAR);
break;
case LOWER_AND_UPPER:
find = concat(LOWER_CHAR, UPPER_CHAR);
break;
}
if (length > find.length) {
repeat = true;
}
final SecureRandom r = new SecureRandom();
if (repeat) {
for (int i = 0; i < length; i++) {
sb.append(find[r.nextInt(find.length)]);
}
} else {
HashSet<Integer> indexset = new HashSet<Integer>();
for (int i = 0; i < length; i++) {
int index = r.nextInt(find.length);
while (indexset.contains(index)) {
index = r.nextInt(find.length);
}
sb.append(find[index]);
indexset.add(index);
}
}
return sb.toString();
}
/**
* 获取随机字符串
*
* @param length 字符串长度
* @param repeat 是否可以存在重复的字符
* @param ch 自定义字符集
*/
public static String getRandomString(int length, boolean repeat, char[]... ch) {
List<Character> list = new LinkedList();
for (char[] cs : ch) {
for (char c : cs) {
list.add(c);
}
}
if (list.size() == 0) {
return "";
}
if (length > list.size()) {
repeat = true;
}
final SecureRandom r = new SecureRandom();
StringBuilder sb = new StringBuilder();
for (int i = 0; i < length; i++) {
if (repeat) {
sb.append(list.get(r.nextInt(list.size())));
} else {
sb.append(list.remove(r.nextInt(list.size())));
}
}
return sb.toString();
}
/**
* 随机获取姓
*
* @return
*/
private static String surname() {
return SURNAME[new Random().nextInt(SURNAME.length - 1)];
}
/**
* 获取N位常用字
*
* @param len
* @return
*/
private static String name(int len) {
StringBuilder ret = new StringBuilder();
for (int i = 0; i < len; i++) {
String str = null;
// 定义高低位
int highPos, lowPos;
Random random = new Random();
//获取高位值
highPos = (176 + Math.abs(random.nextInt(39)));
//获取低位值
lowPos = (161 + Math.abs(random.nextInt(93)));
byte[] b = new byte[2];
b[0] = (new Integer(highPos).byteValue());
b[1] = (new Integer(lowPos).byteValue());
try {
//转成中文
str = new String(b, "GBK");
} catch (UnsupportedEncodingException ex) {
ex.printStackTrace();
}
ret.append(str);
}
return ret.toString();
}
public static void main(String[] args) {
System.out.println(RandomStringUtil.fullName());
}
}
